1. Field of the Invention
This invention relates to a self-closing drawer slide having a housing mounted on an inner end thereof with a catch in the housing that engages a latch on an inner section of the slide to move the slide to a closed position when the inner section moves within a pre-determined distance of the closed position.
2. Description of the Prior Art
It is known to have self-closing drawer slides with a housing affixed at an inner end of the outer slide member. In the Lee U.S. Pat. No. 7,083,243 issued Aug. 1, 2006, the housing has a channel with a cam slider 20 that operates by a leaf spring to move engaging jaws laterally to lock and unlock the cam slider within the channel and to simultaneously disengage and engage respectively an actuating pin in the inner slide member. The cam slide of Lee is relatively complex, expensive and subject to failure and it contains components that move relative to other components of the cam slider. The cam slider also contains a leaf spring that causes the components of the cam slider to move relative to one another. In addition, there is a second spring to move the cam slider along the channel of the housing. The cam slider described in the Lee patent has four separate components that must be assembled and three of the components are movable relative to one another and relative to the fourth component. While the channel of Lee is generally straight, the channel has two indentations to accommodate a reset feature that is also complex and subject to failure, particularly as the cam slider becomes worn with use.
The Lu U.S. Pat. No. 7,159,958, issued Jan. 9, 2007 describes a sliding rail assembly auto-locking structure for a drawer with a movable hook having a front guide rod and a rear guide rod that are coupled to sliding slots of a holder base. The movable hook 6 can pivot about the guide rod at the rear of the movable hook. A spring is connected to a locating device on one side of the movable hook.
The Lu U.S. Pat. No. 7,244,005, issued Jul. 17, 2007 describes a sliding rail assembly auto-locking structure for a drawer. The auto-locking structure has a holder base, a swivel hook connected to a slide 4 that is axially slidably mounted in a longitudinal sliding groove. Two return springs are fastened to hook portions of stop locks of the slide and there is a hydraulic cylinder fastened to a locating groove of the slide to buffer the return stroke of the slide.
Previous devices are complex, expensive, or they do not function properly as the actuator and hook disengage prematurely or cannot be easily reset when the slide moves to the inner end of the housing before engagement with the actuator, or they only function properly when manufactured within strict tolerances, or they fail to function properly when the actuator and hook become slightly worn through usage. Previous self-closing drawer slides that have a reset feature often have an actuator being forced over a hook, thereby increasing the wear between the actuator and the hook, or stretching these components if they are made to be flexible and thereby reducing the proper operation of the self-closing assembly, or causing the assembly to fail prematurely. Further, some previous devices have an actuator that only weakly engages a hook and when the drawer in which the slide is used is opened too quickly by a user, the actuator and hook disengage prematurely, causing the hook to move to the inner end of the housing under the force of the spring, and requiring the assembly to be reset before it can operate when the drawer is closed. Some self-closing mechanisms can only be reset by manually moving the hook into the locked position when the drawer is open.